Fan staying on at all times brivis tek304
this means a limit switch is open, or the thermostat is set to fan on, as opposed to "auto".
Unplug the unit, then plug it back in and watch the sequence.
If it goes through it's normal operation and then the burners shut off, it means the high limit has been triggered. usually this means the furnace is suffocating, remove your filters and try again.
If it works fine the second time you just need new filters. if not then the high limit is bad.
The high limit is inside, near the burners on the back wall connected to 2 wires.
it's easy to replace, order a new one (be sure to get the right temperature setting, it's on the old one). pull the old one out and plug the new one in. the wires don't have sides as long is one is in Common or C, and one is in NC.
If the main fan comes on first and the furnace does not cycle, it means a limit is open (or the thermostat is in fan on mode). The rest of the limits are on the same circuit as the high limit, trace that circuit and push the button on each switch along the way, if one clicks you know you've reset it... you also know that it has been set off, which implies a safety hazard and technically you should call a pro to come see it.
Anyway, continue along the circuit checking each one until you've come to the main circuit board. then plug the furnace back in and watch it go. if that hasn't fixed it, call a professional.
May 06, 2011 |